/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *	  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.sirona.configuration;

import java.util.*;
import java.util.logging.Level;
import java.util.logging.Logger;

// Configuration holder
public final class Configuration {
    private static final Logger LOGGER = Logger.getLogger(Configuration.class.getName());

    public static final String CONFIG_PROPERTY_PREFIX = "org.apache.org.apache.sirona.";

    private static final String[] DEFAULT_CONFIGURATION_FILES = new String[] { "org.apache.sirona.properties",
            "collector-org.apache.sirona.properties" };

    private static final Properties PROPERTIES = new Properties();

    static {
        try {
            final List<ConfigurationProvider> providers = new LinkedList<ConfigurationProvider>();
            for (final String source : DEFAULT_CONFIGURATION_FILES) {
                providers.add(new FileConfigurationProvider(source));
            }
            providers.add(new PropertiesConfigurationProvider(System.getProperties()));
            for (final ConfigurationProvider provider : ServiceLoader.load(ConfigurationProvider.class,
                    Configuration.class.getClassLoader())) {
                providers.add(provider);
            }
            Collections.sort(providers, Sorter.INSTANCE);

            for (final ConfigurationProvider provider : providers) {
                PROPERTIES.putAll(provider.configuration());
            }
        } catch (final Exception e) {
            LOGGER.log(Level.SEVERE, e.getMessage(), e);
        }
    }

    public static boolean is(final String key, final boolean defaultValue) {
        return Boolean.parseBoolean(getProperty(key, Boolean.toString(defaultValue)));
    }

    public static int getInteger(final String key, final int defaultValue) {
        return Integer.parseInt(getProperty(key, Integer.toString(defaultValue)));
    }

    public static String getProperty(final String key, final String defaultValue) {
        final String property = PROPERTIES.getProperty(key, defaultValue);
        if (property != null && property.startsWith("${") && property.endsWith("}")) {
            return getProperty(property.substring("${".length(), property.length() - 1), defaultValue);
        }
        return property;
    }

    public static String[] getArray(final String key, final String[] defaultValue) {
        String property = PROPERTIES.getProperty(key);
        if (property == null) {
            return defaultValue;
        }
        return property.split(";");
    }

    private Configuration() {
        // no-op
    }

    private static class Sorter implements Comparator<ConfigurationProvider> {
        public static final Comparator<? super ConfigurationProvider> INSTANCE = new Sorter();

        @Override
        public int compare(final ConfigurationProvider o1, final ConfigurationProvider o2) {
            return o1.ordinal() - o2.ordinal();
        }
    }
}
